This application relates to analog computation, for example, using analog electronics to compute algebraic functions such as the Fourier transform.
The Fourier transform and many other forms of mathematical operations are widely used in a number of electrical engineering and signal processing applications, for example, to provide signal conversions between the time domain and the frequency domain and to implement time-domain or frequency-domain filters of various types. Many existing techniques to carry out those computations make use of digital signal processors (DSP), in which case variables are represented and processed as discrete-valued signals. Some other techniques to implement those computations make use of analog circuits, such as using resistor-based current summation circuits to achieve summations and multiplications.